Download Climate Change and the Mediterranean Region

Climate Change
and the
Mediterranean Region
Stéphane Hallegatte
Greenhouse gases in the last 10,000 years
Club ViTeCC – 17/12/2008
IPCC, AR4, 2007
Observed climate changes
Change in global mean temperature
Period
Trend
100 years
0.074oC/decade
Club ViTeCC – 17/12/2008
50 years
0.128oC/decade
Observed climate changes and impacts
Sea level rise
Change in
snow cover
Club ViTeCC – 17/12/2008
Future climate change at global scale
Club ViTeCC – 17/12/2008
Focus on the Mediterranean
Region
Club ViTeCC – 17/12/2008
Modeled change in temperature and precipitations between 1990 and 2100
scenario A1B (median)
Club ViTeCC – 17/12/2008
IPCC, 2007
Club ViTeCC – 17/12/2008
Impact on water resources
From IPCC (2007)
Available water
in 17/12/2008
2100 vs.1990
Clubresources
ViTeCC –
Climate change impacts on the
Mediterranean Region
Club ViTeCC – 17/12/2008
The Mediterranean region
Population
22 countries, 420 millions inhabitants (7% of the world population)
100 millions more inhabitants in 2025, essentially in cities of the
southern countries
Ageing population in the North, young population in the South
Economy
13% of world GDP, decreasing because of Asian growth
Average growth rate between 2% in the North and 5% in the South
Key sectors for climate change vulnerability
Water management
Agriculture
Energy
Urbanism
Tourism
Club ViTeCC – 17/12/2008
Water availability
7% of the world population but 3% of water resources
Water scarcity even in absence of climate change:
108 millions inhabitants with less than 1000m3/year
Up to 165 millions inhabitants in this situation in 2025
Highly heterogeneous water resources:
The South has only 13% of the region water resources
Rainfall concentrated over a few weeks in winter
Frequent summer drought during peak demand
Reliance on regulation infrastructure and reservoirs
Water demand: about 200 km3/year, in rapid growth:
65% for agriculture
15% for domestic use
Tourism and industry
Club ViTeCC – 17/12/2008
Climate change and water stress
Number of inhabitants (in millions)
living under increased water stress
(Arnell, 2005).
Colors represent different population
scenarios
Consequences at macroeconomic
scale (agriculture, industry, health,
etc.)
Specific measures are able to reduce water stress:
1. Demand control (using norms or pricing)
2. User priorities and activity changes (e.g., agriculture)
3. Water reuse
4. New storage and transport infrastructure
Club ViTeCC – 17/12/2008
5. Non-conventional supply (e.g., desalinization)
Impacts on agriculture
Agriculture is marginal in the North, but central in the South, where
it provides livelihood for 70 millions inhabitants and produces up to
15% of GDP
Agriculture is mainly rain-fed in the South, with existing
stresses due to desertification, soil degradation, water
salinization
Current deficit in the region agriculture trade balance in spite of
productivity gains
Without adaptation, yields will decrease in the most of the basin
With adaptation, and if water resources are sufficient for
increased irrigation, yields can increase in most places
Agricultural impacts are directly related to water scarcity
Club ViTeCC – 17/12/2008
Impacts on agriculture
Risk of further degradation of the agriculture trade balance
Increased food dependency – Issue for food security
Rain-fed and food-producing agriculture is particularly vulnerable
Shock on small scale farming
Possible acceleration of rural-urban migrations
Problems to accommodate growing population in cities:
Need for massive investments in urban infrastructures
Need to provide jobs and housing
Economic development is the best adaptation strategy,
provided that climate change is taken into account in
development plans
Club ViTeCC – 17/12/2008
Urbanism, between adaptation and
mitigation
Rapidly growing cities in the South, large urban investments
Urban forms cannot change rapidly, Unprecedented need to
anticipate future constraints and objectives
Urban forms matter for greenhouse gas emissions
Urban forms matter for climate-change vulnerability
Urban forms matter for many other policy objectives, e.g., related
to social and spatial inequalities.
An unavoidable uncertainty on future emission targets, energy
prices, and future local climates:
Unprecedented decision-making issues
Club ViTeCC – 17/12/2008
Adapting to one possible climate…
Climate analogues in 2070, Hadley Centre Model, SRES A2
After Hallegatte, Ambrosi, Hourcade (2007)
We know how to build for the climate of Paris
We know how to build for theClub
climate
of Cordoba
ViTeCC
– 17/12/2008
But now, we need to build for both climates
… and to another…
Climate analogues in 2070, Météo-France Model, SRES A2
After Hallegatte, Ambrosi, Hourcade (2007)
Future climate are highly uncertain.
Adaptation and mitigation decision-making
should
take
Club ViTeCC
– 17/12/2008
into account this uncertainty
Future flood risks in Tunis
The poorest
population and
most recent
migrants often live
in highest-risk
areas
Club ViTeCC – 17/12/2008
Energy sector, between mitigation
and adaptation
The region is heavily dependent on fossil fuels
75% in the North - 95% in the South
There is a significant uncertainty on future energy prices:
Recoverable fossil fuel reserves
Geopolitical situation and strategy of Middle-East producers
Climate policy and carbon price
Electricity production depends on water availability
These uncertainties should be taken into account in the decision
making process on energy-consuming investments:
Electricity production
Urban forms and transportation networks
Desalinization
Diversification strategy and development of renewable energy
Club ViTeCC – 17/12/2008
(especially solar and wind)
Tourism, between mitigation and
adaptation
Tourism represents 2 to 12% of GDP
Climate change will affect the attractiveness of all regions
Percent change in the
number of tourists
after a 1°C global
warming.
(source : Hamilton et
al., 2005).
Water resource availability for tourism;
Future prices of international transport:
Fewer but longer trips?
Club ViTeCC – 17/12/2008
More tourists from neighboring regions?
Conclusions
The Mediterranean region will be heavily impacted by
climate change during the 21ème century:
Climate change could exacerbate existing stresses and
inequalities within and among countries
Economic development and poverty reduction are very
efficient tools to reduction climate change vulnerability,
provided that climate change is taken into account in
development plans
Strategic decisions have to be made in a context of climate
and energy risk management
Club ViTeCC – 17/12/2008